Rotary pump



March 23, 1954 L. A. THOMSON ETAL ROTARY PUMP Filed Jan. 12, 1948 s sheets-sheet 1 ll Z]! awe/mm fe 1 moms-or 806/ DaV/c/ moms? March 23, 1954 A. THOMSON ETAL ROTARY PUMP 3 Sheets-Sheet 2 Filed Jan. 12, 1948 JYWM'WM (/2g (720M500 a/m Dav/J no/Was Q wm.gm%

March 23, 1954 L. A. THOMSON ETAL ROTARY PUMP 3 Sheets-$heet 3 Filed Jan. 12, 1948 qgr Patented Mar. 23, l 954 ES PATENT OFFICE.

ROTARY PUMP Leroy A. Thomson and David F. Thomas, Minneapolis, Minn., assignors to Waterous Company, St. Paul, Minn.

Application January 12, 1948, Serial No. 1,723

The present invention relates to an improvement in rotary pumps of a type particularly useful in pumping liquids and semi-liquids.

Various types of rotary pumps have been designed for handling semi-liquid materials or liquids containing solids. Such pumps are often used in conjunction with chemicals, foods of various types, soap, pharmaceuticals, oils, and the like. As a result the pumps must be designed so that they may be used in pumping liquids which contain solids such as pulpy matter, cubes and other such materials. The object of the present invention lies in the provision of a rotary pump which may be used for the pumping of such materials, and which would not be injured by foreign matter in the liquid pumped such as matches, pins, string and the like.

A feature of the present invention lies in the provision of a pump having a pair of inter-acting impellers which are mounted on hub providing a bearing support directly under the rotor load. As a result the impellers are better sup- 4 Claims. (Cl. 103-126) ported to operate at slow speed without vibration or agitation.

A feature of the present invention resides in the provision of a pump having a pair of rotors provided with inwardly extending hubs which engage against a sealing device supported within the housing. The sealing means providing a seal between the impeller shaft and the casing is spaced substantially from the food chamber so that there is little danger of contaminating the material pumped with metal particles produced by the rubbing contact between two relatively movable parts.

A feature of the present invention lies in the provision of dual ports which may be connected either to the intake or to the outlet passage of the pump depending upon the direction of rotation of the impellers. When the impellers rotate in one direction, the dual ports are connected to the inlet of the impeller chamber, while rotation of the impellers in the opposite direction provides dual ports connected to the discharge from the impeller chamber.

An added feature of the present invention lies in the manner in which the impellers are constructed. Two impellers may be simultaneously machined with a single tool, thus saving time in the manufacture of the pump and insuring proper machining of cooperating impellers.

These and other objects and novel features of the invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of the specification:

' Figure 1 is a perspective view of the pump showing the outward appearance thereof.

Figure 2 is a cross sectional view through the parallel impellers and impeller shafts.

Figure 3 is a sectional view through one of the impellers of the pump, the position of "the section being indicated by the line 3-3 of Figure 2.

Figure 4 is a cross sectional view through the pump, the position of the section being indicated by the line 44 of Figure 2.

Figure 5 is a view similar to Figure 4 showing two lobe impellers used in place of the single lobe impellers or Figure 4.

Figure 6 is a diagrammatic view showing a stage in the process of manufacturing theimpellers shown in Figure 5.

Figure '7 is a sectional view through a portionof the pump casing adjacent an impeller hub showing a somewhat different type of packing construction from that shown in the previously described views.

The pump A illustrated in Figures 1 through 4 of the drawings includes an elongated body including a gear case portion [0 and an impeller housing portion integrally or detachably connected by spacing arms l2 and i3. A base plate l4 likewise forms a connection between the two parts If] and II by providing a flange l5 at one end thereof connected to the body portion l0 and a flange "5 at the other end thereof connected to the body portion l The base plate I4 is provided with suitable apertures I1 therethrough by means of which the casing or housing may be secured in fixed position.

The housing portion It includes a casing wall I 9 having a pair of apertures 20 and 2| therethrough in spaced relation through which the impeller shafts 22 and 23 extend. The apertures 20 and 2| are somewhat larger than. the outer diameter of the shafts 22 and 23 and oil seal 24 are interposed between the shafts and the housing at these points.

Hubs 25 and 26 are provided on the wall I9 encircling the apertures 20 and 2|. The apertures 20 and 2| extend through these sleeves 25 and 26. Bearingsleeves 30 and 3| are provided in the apertures 21 and 29 respectively. The shafts 22 and 23 fit snugly within these bearing sleeves and are sufliciently free to rotate.

Gears 32 and 33 are keyed to the shafts 22 and 23 outwardly of the bearings 3|] and 3|. These gears are held in place by nuts 34 and 35 which engage externally threaded portions of the shafts 22 and 23. Smaller diameter portions 35 and 31 of the shafts 22 and 23 project beyond the threaded portions of these shafts. R

A housing closure plate 39 is secured to the end of the housing portion Ill opposite the wall l9 by cap screws 40 or other suitable means. Spaced apertures 4| and 42 extend through the closure plate 39. A bearing 43 is provided within the aperture 4| for accommodating the reduced diameter end portion 36 of the shaft 22. A circular aperture 45 of larger diameter than the aperture 4| is provided inltheexterior surfaceof the plate 39 in alignment withptheapertures M and 44. A plug 4'! of steel or other suitable material is provided in the aperture 45 to enclose the end of the shaft 22.

A hearing 49 is positioned in the aperture 42 and an oil seal 5|] is positionedin the .aperture .42

outwardly of the bearing. Thereducedrdiameter. end 31 of the shaft 23 projects through the closure plate 39 and is providedwith asplined end.

or provided with a key way 5| for accommodation of a suitable key for connecting the shaf-tto.

a drive element.

Thus .it. will. be seen. that the. gears which.v connect the shafts and. .23 .andwhich cause xrota.- tion thereofdin .unison are .sealed within the gear chamber. and suitable lubricant may be placed in this chamber for lubricating the gears.- This lubricantis spaced fronrthe pumping chamber andQthere .is :virtually no danger. of. the lubricant entering this pump chamber.

Therpump housing .includes a peripheral wall 52..which=is..c1osed on one endby ,an integral closure wall '3, as best illustratedin Figure3 of thetdrawings. This wall. 53 vis of varying. thickness-,beingrelatiyely thinnear its upper extremity as illustrated in this figure andbeing substantia1ly -thicker throughout. the sides. and lowerportiQmthereo f...

--As illustratedinFigure .4 of the drawings apair oi ropp'ositely,dispoeedports 54 and .55 are .provided in the wall 52 on opposite sides of ;the casing These ports .54and 55 lead to cored passages 56.and.51,,. respectively, which communicate withiaiorwardly extending port 59 leading into the .interior. .of the impeller housing-as shown. in Figure 5 or the, drawings. The central jupper portionl ofuthe .wall- 53 "is also thickened: as indicatedat .60, and aport fi on the top of the housing comrnunicates with a-downwardly extending passage =62 terminating in a forwardly extending coredpassage '63 leading into the impeller cham-v ber. Whentheimpellers rotate in; one direction the passage 59 .acts.as the intake and the passage 63 acts as the outlet. Whenthe-direction. of rotation oi the impellers is reversed, the. passage 63-acts as theinlet. and the.-passage.59 acts.,as the outlet:

The-.wall.-53 is providedwith two forwardly extending gintegral sleeves or hollow bosses 64 .and 65. Theeimpellers oG- and 5'! .rotate about these sleeves. :and .165. They impellers aresimilarly constructed and are shaped as best illustratedin Figure .4 of'zthe drawings. Each impeller includes a generally semii-cylindrical-piston 69- having arcuateends T0 and H, The semi-cylindricalpistons-.159 .are-rprovided with concentric outer and inner cylindrical surfaces 12 and 13a The outer surface: 12 iszof proper diameter to fit with a run ning fit within-thecylindricalinnersurface-14 of the impel-ler'chamber- 15.. One such cylindrical innensurfaceafl is provided for each of. therim pellers 66 and.

The inner .cy-l indrical=sur=face '13 of a each piston is of proper diameter to fit with.a running fit about-thesoutersurface of a sleeve 64x01? 65. The piston also is of:.;proper de'pth to *fit closely lads jacentcthezzouter surface-of the 'Wall:.;53 and againstzthe :closurewp'late i6; Thusithe pistons iamsubstantially 'fill :a ;.portion of i the impeller chambers-as theyrotatai The pistons 69 are supported upon supporting discs 1'! which are secured marginally to the pistons. Each disc TI is attached to a sleeve or hub '19. This sleeve or hub 19 fits upon a reduced diameter end of its respective shaft22 or 23 and is keyed thereto torrotate therewith; The impeller 66 is mounted upon the reduced diameter end of, the shaft 22 while the impeller 61 is secured to..thev reduced diameter end 8| of the shaft 23.

The impeller hubs l9 abut against shoulders in the shaftsfiformedl'between the reduced diameter endssthereofiandfithe remainder of the shafts. Theshafts are-provided with threaded ends to accommodatenuts2 and 83 which hold the impellers in place.

The closure plate 16 is secured to the peripheral wall 52 of the pump housing by cap screws 84 or other suitable-means; The closure :plate is providedij. with; two 1 adj acent 1 circular. :rapertunes 85 and 86 toaccommodatemhe-dis'cscl! ofitheime. pellers? The closureplate-l 6 is likewiseprovided withgrecesses .281 and-.289 aligned. .:with the. aper+ tures 85:;and; 86 tezaccommodate: the nuts. .082 and 83.:

Asgis ,common-inpumps of; this. type the sleeves B4 andrliss.area-notchedv on one .side .as indicated at 92 ion' the same xradii as the :h'ousing -surfaces 14 so "that F the i impellers =may fit closely together; The impellers are so timed that the piston of one impeller follows closely the 'piston 'of theother impeller in therotati'on thereof. Thus. the space between the-impellers is at all times sealedjwhile liquid or partial liquidmay be carried about the periphery of the impeller-chamber-by the 'pis'ton from the inlet to the outlet.

-An aperture 93 is provided'in'the W2;1153 "ene circling each "of -the shafts"22"and 23; Aq-seal-is provided between the hub 19 of each impeller and the-baseor shoulder-endsgpf "the apertures-'93." As bestillustra-tedinFigures 2 and 3"of the ;draw-- ings, a collar 94 encircles each shaft adjacentthe imp el'ler'hub "79 and insur'face contact therewith. Apacking is provided at the basepr shoulder end-of each aperture 33." Each packingincludes cooperable; male and T'female" 'a'da'pte'r -rings :95 having 1 special Llefather lpacking washers .198, IV? shaped insection .therebetween'... A spring. 36 'is interpose'dpetween the. male, adapter 95 "andlthe collar 94." Thus. the :packingisj urged against the base preach aperture .93 .to,.,seal the casing .rela-, tive to the rotating shaft. The collars -,.94-.fit against. the ends. of, the. hubs landnormally are heldirom rotation-by suitable key pins. .onthe like. while the hubs rotate.

In. Figure .5 .of the .drawings weillustrate .a modified .form; of; construction which. is indicatedin-zgeneral by-the'letter ;B.. The pumpg-B isuvir-x tually identical .to the previously described pump Anwi-th-z the exception: that .thepump B ispros: vided with. two lobe impellers or :two 291511011" ims pellers rather than singlenpiston impellersze' The double lobedimpellers are preferable where high speeds are required because of the fact l-thatsthe lobes. balance one anotheria-ndz-dopnot exert as great a strain on the-supporting shafts.

Inxthermonstruction :shown: in- Figure 5,; the pump housing ;may;-'be -.--considered *r-identical. to. thatwprev-iously; described. Sleeves :65 and :66 project; fromithe; housing 1 wall 53 concentric with thezcylindnical'innerjsuriaces m of the impeller chamber 15.; Theimpellerssllland-99 are provided with two pistons or lobes I50 and |0 |--,-pro-- jectingwfrom. opposite sides of r the supporting discs. The impellers arelprovideduwithihubs= I02 and I03 which are supported on the shafts 22 and 23. In the pump B the pistons I90 and I! are of an areuate length. equal substantially to onefourth the circumference of a cylinder and are provided with; arouate ends so that the trailing edge of one lobe may fit closely adjacent the leading edge of a lobe of the other impeller in the rotation thereof.

In Figure 6 of the drawings is disclosed a manner in which the impellers 9"! and 99 are machined so that two impellers may be simultaneously produced. Each impeller is first turned in a suitable machine to provide cylindrical outer surfaces I94 on the lobes and concentric inner cylindrical surfaces I thereupon. The outer and inner surfaces of the impellers are also turned to produce the proper impeller thickness and the discs Hi6 are machined to the proper size and shape.

Iwo impellers such as 9'5 and 99 are then seecured in parallel relationship as indicated in Figure 6 and a. boring cutter or tool III'I is used to produce the arc-uate ends I09 and M8 on the pistons. This boring cutter III'I is positioned to simultaneously produce arcuate ends on one end of all four pistons simultaneously. The position of the impellers is then reversed and the boring tool I0! is again used to simultaneously form arcuate surfaces on the other ends of all of the pistons.

In Figure 7 of the drawings we disclose a modified form of seal. This form. of seal is designed to take the place of that previously described in conjunction with the pump A. In this form. of seal the shafts III are provided with a pair of spaced flanges H2 and H3 at the end of the reduced diameter portion I I4 thereof. An 0 ring H5 is placed between the flanges H2 and H3. This 0 ring comprises a ring of rubber or other suitable material which is compressed between the shaft H4 and the inner surface of a collar H6. This collar II6 abuts against the impeller hub I I! on one side and against a second collar I I9 on its opposite side.

A sleeve I freely encircles the shaft III and is integral with the collar H9. A shoulder I2I between two different diameter portions of the apertures I22 is provided outwardly of the sleeve I20. A pair of washers I23 having an O ring or rubber packing ring I24 therebetween encircles the sleeve I20 adjacent the shoulder I2I. A spring I25 is provided between one washer I23 and the collar I I 9.

In operation the collar I I6 rotates with the shaft and the hub III. The collar H9 is keyed to or otherwise held from rotation relative to the housing of the pump. A running seal is provided between the collars H6 and H9.

In a pump of the type described it is important that the various parts coming in contact with the food or other material being pumped be accessible for cleaning purposes. It will be noted that the closure plate 16 may be removed by removing the cap screws 84. If preferred these can screws may comprise wing nuts for easier removal. By loosening the nuts 82 and 03 the impellers may be removed from their respective shafts. The compression of the springs 96 then tends to force the collars 94 outwardly. If desired the entire seal may be removed. Thus in cleaning the pump, it is necessary to remove but an extremely small number of parts so that the pump may be easily dis mantled and assembled.

In accordance with the patent statutes, we

have described the principles of construction and operation of our rotary pump, and while it has been endeavored to set forth the best embodiments thereof, it is desired to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of the present invention.

We claim:

1. In a rotary pump, a housing, an impeller chamber in said housing, a pair of hollow bosses on said housing extending into said chamber in spaced relation, a pair of shafts extending through said hollow bosses and spaced therefrom, impellers mounted upon said shafts, said impellers including a hub interposed between each shaft and the corresponding boss for that shaft, a disc secured to said hub at one end thereof, and a segmental piston marginally secured to said disc, each said piston having a cylindrical inner surface fitting closely about its corresponding boss, the hollow bosses extending beyond the impeller hubs and having a shoulder therein spaced from the hubs, and a seal interposed between each said shoulder and a corresponding hub, said bosses supporting said hubs with a running lit to provide a bearing therefor, this bearing forming the sole support for said shafts within said housing.

2. The structure described in claim 1 and in which the housing includes recesses axially aligned with said shafts and encircling the same, and impeller retaining means on said shafts within, and in spaced relation to, the walls of said recesses.

3. A pump seal for use in a rotary pump having an impeller hub, a housing boss having a hollow passage therethrough serving as a bearing for the hub, and a shoulder within said boss spaced from said hub, the seal including a resilient ring encircling said shaft and held from. longitudinal movement thereon, a collar encircling said resilient ring and abutting against an end of the hub, a second collar engaging the side of the first named collar opposite that abutting the hub, and spring means interposed between said shoulder and said second collar.

4. The structure defined in claim 3 and including packing means between said spring means and the said shoulder.

LEROY A. THOMSON. DAVID F. THOMAS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 628,906 Grlndrod July 11, 1899 1,497,050 Wardwell June 10, 1924 1,642,454 Malmstrom Sept. 13, 1927 1,853,430 Jensen Apr. 12, 1932 1,877,688 Peterson Sept. 13, 1932 1,891,612 Schmidt Dec. 20, 1932 1,902,347 Vogt et a1. Mar. 21, 1933 2,096,490 Hansen Oct. 19, 1937 2,161,729 Thomson June 6, 1939 2,193,273 Dietzel 0 Mar. 12, 1940 2,228,933 Thomson Jan. 14, 1941 2,247,454 Thomson July 1, 1941 2,269,200 Hillner Jan. 6, 1942 2,279,136 Funk Apr. 7, 1942 2,372,816 Deschamps et a1. Apr. 3, 1945 FOREIGN PATENTS Number Country Date 2,572 Great Britain of 1868 

